1. Field of the Invention
The present invention relates to a color LED display device, in particular to the color LED display device using a micro optical device assembly to change a light path, such that red light, green light and blue light can be combined onto a two-dimensional plane to improve the color separation phenomenon.
2. Description of the Related Art
In recent years, light emitting diode (LED) is used extensively in LED illumination device, LED display device and LED backlight module, wherein the LED display device is commonly used in advertising billboards and traffic indicating devices. With reference to FIG. 1 for the architecture of a conventional monochrome LED display device, the conventional monochrome LED display device 10′ generally comprises a main frame 109′, at least one display module 105′, at least one cable 106′, at least one connector 107′, and at least one main control module 108′, wherein the conventional monochrome LED display device 10′ as shown in FIG. 1 has three display modules 105′ and two connectors 107′, and the display module 105′ has a plurality of monochrome LED components 1051′. The cable 106′ is electrically coupled to the three display modules 105′ and the main control module 108′. The main control module 108′ comprises a control unit 1081′ and a power supply unit 1082′, wherein the power supply unit 1082′ can supply a power source to the LED component 1051′; the control unit 1081′ can control all LED components 1051′ to emit light or turn off. Therefore, the display module 105′ can display specific numbers, graphics or texts.
Since the monochrome LED display device cannot display color numbers, graphics or texts, therefore LED display device manufacturers introduce a color LED display device. With reference to FIG. 2 for a perspective view of a conventional color LED display device, the conventional color LED display device 1a comprises: a substrate 10a, a flexible circuit board 30a and a plurality of LED display units 20a, wherein the substrate 10a includes two power supply holes 11a. 
With reference to FIG. 3 for a perspective view of an LED display unit of a conventional color LED display device, the LED display unit 20a further comprises: a casing 201a, a driving chip 202a, a green light LED chip 203a, a red light LED chip 204a, and a blue light LED chip 205a, wherein the green light LED chip 203a, the red light LED chip 204a and the blue light LED chip 205a are coupled to the driving chip 202a, and represent pixel respectively. The green light LED chip 203a, the red light LED chip 204a and the blue light LED chip 205a are driven by the driving chip 202a to emit light. In FIG. 2, when a portion or all of the LED display units 20a emit light, the conventional color LED display device 1a can display color numbers, graphics or texts.
With reference to FIG. 4 for a cross-sectional side view of the conventional color LED display device, the conventional color LED display device 1a comes with a simple structure and a low manufacturing cost. However, the display unit 20a as shown in FIG. 4 does not have other optical components such as the refractive lens, so that when the driving chip 202a drives the green light LED chip 203a, the red light LED chip 204a and the blue light LED chip 205a in the display unit 20a to emit light, a green light G′, a red light R′ and a blue light B′ will not be refracted by emitted directly from the display unit 20a, and the green light G′, the red light R′ and the blue light B′ cannot be combined on a two-dimensional plane. As a result, when a user views the images at a near distance, the user will see the three separated color lights of the conventional color LED display device 1a. In other words, the conventional color LED display device 1a has the drawback of the color separation phenomenon.
In addition the light emission of the LED chip will generate heat, so that the distance between the green light LED chip 203a, the red light LED chip 204a and the blue light LED chip 205a of the conventional color LED display device 1a is generally too short, and the distance between two adjacent LED chips must be over 0.2 mm, and thus the method of reducing the distance between the LED chips in order to overcome the color separation problem of the conventional color LED display device 1a cannot be used.
In view of the aforementioned problems of the conventional monochrome LED display device and color LED display device that cannot display color numbers, graphics or texts and having the color separation phenomenon, the inventor of the present invention conducted extensive researches and experiments, and finally developed a color LED display device without color separation in accordance with the present invention to overcome the drawbacks of the prior art.